Cam Fastener Rotor Mounting for Thin Profile and Maintenance
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Solution Overview
Problem
Current rotor mounting systems to motor shafts face issues such as added thickness, limited accessibility for maintenance, inconsistent clamping forces, high manufacturing costs, and assembly errors, which compromise the thin axial profile and reliability of modular magnetic encoder rotors.
Innovation Solution
The use of cam screws to securely mount the rotor to a motor shaft, providing accessible and consistent clamping forces without the need for external hubs or complex internal structures, allowing for easy maintenance and repositioning while maintaining a thin profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If set screws are inserted through holes in an external hub to engage the motor shaft, then the rotor can be repositioned after stator housing is fixed, but the external hub adds thickness to the overall rotor, defeating the thin axial profile advantage
Solution Approach 1:
The invention removes the external hub from the rotor design entirely. Instead, set screws are positioned within the working thickness of the rotor itself, engaging the motor shaft through holes that pass through the rotor's thickness. This extraction of the hub eliminates the added axial thickness while maintaining the repositionability function through the accessible set screw holes.
Solution Approach 2:
The invention transitions from a radial hub structure (extending outward from the rotor face) to an axial fastening approach where set screws pass through the thickness of the rotor. This dimensional change allows the fastening mechanism to be integrated within the rotor's existing thickness rather than adding to it externally.
2Length of moving object
If set screws are positioned within the working thickness of the rotor to engage the motor shaft through holes, then the thin axial profile is maintained, but the side edge of the rotor becomes inaccessible after mounting the stator housing
Solution Approach 1:
The invention creates asymmetric access by positioning the set screw holes and corresponding rotor features such that one side of the rotor (the non-marker side) provides access to the fastening mechanism. This asymmetric design allows maintenance personnel to reach the set screws through the stator housing from the accessible side, while the marker track occupies the other side.
3Length of moving object
If set screws are used to secure the rotor to the motor shaft with holes extending through the entire rotor thickness, then the rotor maintains thin axial profile, but it is more difficult to reliably achieve maximum clamping force with set screw tightening tools
Solution Approach 1:
The invention incorporates preliminary positioning features such as tapered holes or locating surfaces that guide the set screws into proper alignment and initial contact with the motor shaft. This preliminary action ensures that the set screws are pre-positioned optimally before final tightening, making it easier to achieve maximum and consistent clamping force.
4Ease of manufacture
If a rotor with internal hub and slotted spokes is used, then the rotor can be mounted on the motor shaft, but the space between spokes must be wide enough for tightening tools, limiting the range of motor shaft diameters
Solution Approach 1:
The invention designs the set screw holes and fastening mechanism to be universal across different motor shaft diameters. By using adjustable set screw positions and proportional hole placements that scale with rotor size, the same basic fastening approach can accommodate a wide range of motor shaft diameters without requiring different rotor designs or spoke configurations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution achieves reliable and consistent clamping forces comparable to set screw methods, reduces manufacturing costs, and allows for easy maintenance access without compromising the rotor's thin profile, enhancing the rotor's operational stability and reducing the risk of assembly errors.
Implementation Method 1
A rotor is disclosed which incorporates cam-type fasteners, such as cam screws, for mounting the rotor to a motor shaft
Data Source
AI summary
A rotor assembly for mounting a rotor to a motor shaft having a rotor with a centrally positioned central bore, the diameter of which is slightly larger than a diameter of the motor shaft, a first stepped bore intersecting the central bore and being aligned along a first axis of the rotor, and a second stepped bore also intersecting the central bore and being aligned along a second axis of the rotor. A first cam fastener is disposed within the first stepped bore, and a second cam fastener is disposed within the second stepped bore. Upon rotating the first and second cam fasteners, they engage the motor shaft thereby securely clamping the rotor to the motor shaft.